Gold-catalyzed simultaneous formation of C-C, C=O, and C-F bonds in the presence of selectfluor: A synthesis of fluoroindenes from allene esters

Article abstract of DOI:10.1021/jo3006528

An approach for the synthesis of fluorinated indene derivatives has been developed via a gold-catalyzed three-component tandem reaction between allene esters, Selectfluor, and water.

Full text of DOI:10.1021/jo3006528

Subscriber access provided by EDINBURGH UNIVERSITY LIBRARY | @ http://www.lib.ed.ac.uk
Note
Gold-Catalyzed Simultaneous Formation of C-C, C=O, and C-F bonds in the
Presence of Selectfluor: A Synthesis of Fluoroindenes from Allene Esters
Yunkui Liu, Jie Zhu, Jianqiang Qian, and Zhenyuan Xu
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/jo3006528 • Publication Date (Web): 30 May 2012
Downloaded from http://pubs.acs.org on June 3, 2012
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a free service to the research community to expedite the
dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts
appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been
fully peer reviewed, but should not be considered the official version of record. They are accessible to all
readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered
to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published
in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just
Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor
changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers
and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors
or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
The Journal of Organic Chemistry is published by the American Chemical Society.
1155 Sixteenth Street N.W., Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 25
The Journal of Organic Chemistry
1
2
3
4
5
Gold-Catalyzed Simultaneous Formation of C−C, C=O, and C−F bonds in the
6
7
Presence of Selectfluor: A Synthesis of Fluoroindenes from Allene Esters
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Yunkui Liu,*,†,‡ Jie Zhu,† Jianqiang, Qian,† and Zhenyuan Xu†
† State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University
of Technology, Hangzhou 310014, People’s Republic of China, and
‡ College of Chemistry & Materials Engineering, Wenzhou University, Zhejiang Province, Wenzhou
325027, People’s Republic of China
E-mail: ykuiliu@zjut.edu.cn
Cl
Ph3PAuNTf2 (5 mol %)
Selectfluor
(2 equiv)
NaHCO3 (2 equiv)
O
MeCN, H2 (20 equiv), 60 °C, 4 h
.
18 examples, 41 86% yields
O
C
2Et
ABSTRACT: An approach for the synthesis of fluorinated indene derivatives has been developed via a
gold-catalyzed three-component tandem reaction between allene esters, Selectfluor, and water.
Recently, much attention has been paid to indene derivatives not only due to their broad range of
biological and pharmacological activities,1 but also due to their potential applications in material
1
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 2 of 25
1
2
3
4
5
6
7
8
9
science.2 It is reasonable to expect that fluorinated indene derivatives will have interesting biological
activities and physical properties since the introduction of the fluorine atom into parent molecules may
significantly affect their original properties such as solubility, biological activity, metabolicstability,
and physical properties.3 Indeed, some fluorinated indene derivatives, e.g. fluoroindanols,4 can be used
as appetite depressants. Besides, some fluorinated indene derivatives, e.g. 1,1,6,7-tetrafluoroindanes,5
can be applied in material science as liquid crystal displaying materials. Regarding their preparation, in
contrast to the rich chemistry of the preparation of indenes,1,2,6−7 efficient methods for the preparation
of fluorinated indene derivatives remain quite limited.8−10 Most of the existing methods for the
synthesis of fluorinated indenes5,11−19 suffer from one or more limitations with respect to multi-step
procedures, not easy availability of the starting materials, harsh reaction conditions, low chemo- or
regioselectivity, and lack of generality. As such, it is still desirable to develop efficient approaches for
the preparation of fluoroindenes from simple and readily available substrates.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
On the other hand, gold-catalyzed tandem reactions,20−22 often involving multi-fold formations of
chemical bonds in a single synthetic process, have proven to be a powerful tool for the construction of
molecular diversity and structural complexity from simple substrates.23−31 In this context, recent
interest has focused on the development of tandem reactions involving Au(I)/Au(III) redox catalytic
systems29−35 because such catalytic systems open up new avenues for building up complex molecules
otherwise difficult to be accomplished with conventional single Au(I) or Au(III) catalytic systems. For
example, Gouverneur et al.32 have recently reported such a redox reaction involving the
2
ACS Paragon Plus Environment

Page 3 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
gold(I)/Selectfluor36,37 system-catalyzed intramolecular oxidative cross-couplings using allenoate esters
to generate tricyclic dihydroindene derivatives. As our ongoing interest in the gold(I)/Selectfluor
system-catalyzed oxidation reactions,33,29−31 we herein report a gold(I)-catalyzed three-component
tandem reaction between allene esters,38−43 Selectfluor, and water where a simultaneous formation of
C−C, C=O, and C−F bonds within a single synthetic step leading to the synthesis of fluorinated indenes
has been achieved involving a Au(I)/Au(III) catalytic cycle.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
In light of our recent success in the gold(I)-catalyzed fluoroamination of alkynes in the presence of
Selectfluor,33 we envisioned that allenoate esters would undergo the fluorolactonization to give
4-fluorobutenolide derivatives under the gold(I)/Selectfluor catalytic system.44−46 For an initial study,
ethyl 2-benzylpenta-2,3-dienoate 1a was treated with 2 equiv of Selectfluor and NaHCO3 in the
presence of 5 mol % of AuCl in no-dehydrated CH3CN at 60 °C for 4 h. No 4-fluorobutenolide
derivative 3a was obtained while a fluoroindene product 2a was isolated in 52% yield (entry 1, Table
1). Our interest in the simultaneous formation of C−C, C=O, and C−F bonds in the reaction leading to
the synthesis of fluorinated indenes prompted us to optimize the reaction conditions so as to make the
reaction synthetically valuable (Table 1). When the reaction was conducted in the presence of 20 equiv
of water under otherwise identical reaction conditions as the entry 1, the yield of 2a was improved to
57% (entry 2, Table 1). An employment of AuCl/AgOTf catalytic system lowered the yield of 2a to
50% (entry 3, Table 1). Neutral Ph3PAuCl and its cationic analogs showed better catalytic activities for
the reaction than AuCl (entries 4–10 vs 2, Table 1), among which Ph3PAuNTf2 was identified as the
3
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 4 of 25
1
2
3
4
5
6
7
8
9
best catalyst, affording the desired product 2a in 73% yield (entry 10, Table 1). Using the same catalyst
but running the reaction at 40 °C lowered the yield of 2a even at a prolonged reaction time (entry 11,
Table 1). The catalytic performances of several other gold(I) and gold(III) catalysts including
(2-biphenyl)Cy2PAuCl, Me2SAuNTf2, IMeSAuNTf2 (IMes = 1,3-bis(mesityl)imidazol-2-ylidene),
AuCl3, AuCl3/3AgOTf, and AuCl3/3AgNTf2 were investigated, all showed inferior catalytic activities
than that of Ph3PAuNTf2 (entries 23–28 vs 10). It was found that both base and solvent had a
significant effect on the outcome of the reaction. The reaction gave no desired product 2a without a
base (entry 12, Table 1). Among several bases (entries 10，13–17, Table 1) and solvents (entries 10,
18–21, Table 1) screened, NaHCO3 was proven to be the best choice of base and CH3CN to be the best
choice of solvent. When the reaction was conducted in the dehydrated CH3CN without addition of
water, a low yield of 2a was obtained (entry 22, Table 1). Control experiments showed that no desired
product was detected in the absence of Selectfluor or a gold catalyst (entries 22, 30, Table 1). Moreover,
several conventional Lewis acids such as CuI, PdCl2, and FeCl3 were surveyed as a catalyst for the
reaction, all failed to furnish the target product 2a even at a catalyst loading of 30 mol% (entry 29,
Table 1), thus highlighting the unique catalytic activity of gold for the present tandem reaction.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
TABLE 1. Screening of Catalyst, Solvent, and Basea
catalyst (5 mol %)
Selectfluor (2 equiv)
F
H2O, base (2 equiv)
F
solvent, 60 °C, 4 h
.
O
O
CO2Et
2a
O
CO2Et
3a
1a
(no formation)
4
ACS Paragon Plus Environment

Page 5 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
entry
1
catalyst
AuCl
solvent
CH3CN
CH3CN
CH3CN
CH3CN
base
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
none
yield (%)b
52c
57
50
68
64
59
62
67
69
73
40d, 42d,e
0
2
AuCl
3
AuCl/AgOTf
Ph3PAuCl
4
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
5
Ph3PAuCl/AgOTf
Ph3PAuCl/AgSbF6
Ph3PAuCl/AgF
Ph3PAuCl/AgCN
Ph3PAuCl/AgNO2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
Ph3PAuNTf2
(2-biphenyl)Cy2PAuCl
Me2SAuNTf2
IMeSAuNTf2
AuCl3
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
toluene
DCEf
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Na2CO3
NaOH
63
63
41
60
6
KOH
KF
CH3COOK
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
NaHCO3
0
0
THF
0
1,4-dioxane
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
27
28g, 0h
67
30
0
67
52
59
0
AuCl3/3AgOTf
AuCl3/3AgNTf2
Lewis acidsi,j
none
0
aAll reactions were carried out with 1a (0.2 mmol), catalyst (5 mol % based on 1a), Selectfluor (2
equiv), H2O (20 equiv), and base (2 equiv) in solvent (2 mL) at 60 °C for 4 h unless otherwise noted.
bIsolated yields. cThe reaction was conducted in the no-dehydrated CH3CN without addition of water.
dThe reaction was carried out at 40 °C. The reaction time was 10 h. DCE = 1,2-dichloroethane.
gOnly the dehydrated CH3CN was used without addition of water. In the absence of Selectfluor.
e
f
h
iLewis acids, such as CuI, PdCl2, and FeCl3. jThe amount of catalyst is 30 mol %.
5
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 6 of 25
1
2
3
4
5
6
7
8
9
After establishing the optimal reaction conditions, we then devoted our efforts to examine the scope
of the reaction and the results are shown in Table 2. Firstly, a variety of ethyl allenoates were subjected
to react with Selectfluor and water under the optimized reaction conditions. In most cases, the reaction
proceeded smoothly to give the corresponding fluoroindenes in moderate to good yields regardless of
the R1 group being an alkyl (44−84%, 2a−2g, entries 1−7, Table 2) or an aryl group (66%, 2h, entry 8,
Table 2). Unfortunately, a terminal allene ester 1u failed to give the desired fluoroindene product 2u
(entry 21, Table 2). When ethyl allenoate 1g bearing two benzyl groups was used as a substrate, only
the benzyl group adjacent to the ester group was annulated into an indene ring while leaving the other
one intact, demonstrating the high regioselective manner of the reaction (entry 7, Table 2). Then,
variation of the ester group of allene 1 was examined. A range of other alkyl groups of R2 including
methyl, n-propyl, i-propyl, n-butyl, and even allyl group could be survived under the reaction
conditions, and the desired fluoroindenes were obtained in moderate to good yields (41−86%, 2i−2o,
entries 9−15, Table 2). However, when a tert-butyl allenoate 1v was subjected to the reaction
conditions, only a butenolide product 3v rather than a fluoroindene product was isolated in 59%
(equation 1, Scheme 1).32,46 This result was similar to that reported by Gouverneur et al.32 in which
case 10 mol % of Ph3PAuNTf2 was used at room temperature. Furthermore, it was found that the
benzyl group with 3-position substituted by methyl, Cl, or Br group could also be annulated into an
indene ring (2p−2r, entries 16–18, Table 2) while 2- or 4-position substituted benzyl groups failed to
be annulated (2s, 2t, entries 19, 20, Table 2). It was found that a tetrasubstituted allene 1w failed to
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
6
ACS Paragon Plus Environment

Page 7 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
furnish the fluoroindene product while a 4-fluorobutenolide product 4w was isolated in 41% yield
(equation 2, Scheme 1).44−46 This study together with the works of Gouverneur group32 demonstrated
that a subtle structural variation of allenoate esters could result in completely different product patterns
in the gold(I)/Selectfluor system-catalyzed cyclization of allenoate esters. Finally, when ethyl
2-phenethylpenta-2,3-dienoate 1x was subjected to the standard reaction conditions, a six-membered
cyclic compound 2x was selectively obtained in 43% yield (equation 3, Scheme 1). The formation of
the fluoroindene scaffold was ambiguously established on the basis of the spectral analyses, which was
further confirmed by X-ray diffraction analysis of a related derivative 2q (Figure S1, Supporting
Information).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
TABLE 2. Gold(I)-catalyzed Synthesis of Fluorinated Indenes from Allene Estersa
R3
R3
3
4
3
4
Ph3PAuNTf2 (5 mol %)
2
2
Selectfluor (2 equiv)
NaHCO3 (2 equiv)
1
1
R1
F
.
CH3CN, H2O (20 equiv), 60 °C, 4 h
R1
CO2R2
CO2R2
O
1
2
entry
R1
R2
Et
R3
H
H
H
H
H
H
H
H
H
H
product
2a
yield (%)b
1
2
3
4
5
6
7
8
9
10
Me
Et
73
68
84
63
44
61
45
66
64
86
Et
2b
2c
n-Pr
n-Bu
Et
Et
2d
2e
n-C5H11
n-C6H13
Bn
Et
Et
2f
Et
2g
Ph
Et
2h
2i
Me
Me
n-Pr
Me
2j
7
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 8 of 25
1
2
3
4
5
6
7
8
9
11
12
13
14
15
16
17
18
19
20
21
Me
Me
Me
n-Bu
Ph
i-Pr
n-Bu
allyl
Me
Me
Et
H
2k
2l
84
81
71
41
75
76
69
61
0
H
H
2m
2n
2o
2p
2q
2r
2s
H
H
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Me
Me
Me
Me
Me
H
3-Me
3-Cl
3-Br
2-Me
4-Me
H
Et
Et
Et
Et
2t
0
Et
2u
0
aAll reactions were carried out with 1 (0.2 mmol), Ph3PauNTf2 (5 mol % based on 1a), Selectfluor (2
equiv), H2O (20 equiv), and NaHCO3 (2 equiv) in CH3CN (2 mL) at 60 °C for 4 h. bIsolated yields.
SCHEME 1. Gold(I)-catalyzed Cyclization of Allene Esters 1v, 1w, and 1x
Ph3PAuNTf2 (5 mol %)
Selectfluor (2 equiv)
NaHCO3 (2 equiv)
(1)
CH3CN, H2O (20 equiv), 60 °C, 4 h
yield = 59%
O
.
1v
O
t
CO2 Bu
3v
Ph3PAuNTf2 (5 mol %)
F
Selectfluor (2 equiv)
NaHCO3 (2 equiv)
.
(2)
O
OEt
O
CH3CN, H2O (20 equiv), 60 °C, 4 h
yield = 41%
O
1w
4w
Ph3PAuNTf2 (5 mol %)
Selectfluor (2 equiv)
NaHCO3 (2 equiv)
(3)
CO2Et
CH3CN, H2O (20 equiv), 60 °C, 4 h
yield = 43%
.
1x
O
CO2Et
2x
8
ACS Paragon Plus Environment

Page 9 of 25
The Journal of Organic Chemistry
1
2
3
4
SCHEME 2. Preliminary Mechanistic Studies
5
6
7
8
9
Ph3PAuNTf2 (5 mol %)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Selectfluor (2 equiv)
NaHCO3 (2 equiv)
F
(1)
.
CH3CN, 18OH2 (20 equiv), 60 °C, 4 h
yield = 70%
CO2Et
18O
CO2Et
1a
2a-18O (m/z: 273.10 [M+Na]+ )
D(H)
Ph3PAuNTf2 (5 mol %)
D(H)
Selectfluor (2 equiv)
NaHCO3 (2 equiv)
F
(2)
.
CH3CN, H2O (20 equiv), 60 °C, 4 h
yield = 71%
CO2Et
O
CO2Et
1a-D
2a-D (m/z: 250.0983 [M+H]+ )
(>99% D-enrichment)
(70% D-enrichment)
SCHEME 3. Proposed Mechanism
R3
H2O
Au(I)
R1
.
A
H+
Path I
CO2R2
1
R3
F
Selectfluor
Path II
Au(I)
L
Au(III)
+
L
R3
R3
I
Au
R1
H2O
i), 1,3-H shift
ii), alcohol oxidation
1
HO
CO2R2
α
reductive
iii), -fluorination of ketone
H+
B
elimination
H
H
HO
R1
F
R1
R3
CO2R2
CO2R2
R3
O
E
Cl
N
2
+
N
_
+
L
III
+
Au
2 BF4
L
F
III
F Au
HO
cycloauration
CO2R2
CO2R2
+
R1
D
HO
R1
C
Base
BH
9
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 10 of 25
1
2
3
4
5
6
7
8
9
Several experiments were performed to gain a mechanistic insight into the present reaction. An
18OH2-labelling experiment unambiguously established that the oxygen atom in the resulting ketone
carbonyl group of 2 originated from water (equation 1, Scheme 2, also see Supporting Information).
The reaction exhibited a primary kinetic isotope effect in the intramolecular competition experiment
(kH/kD = 2.3) (equation 2, Scheme 2, also see Supporting Information), suggesting a rate-determining
cycloauration step.32,35 Based on these results and the previous reports,29−35,47 a possible mechanism
concerning the gold-catalyzed three-component tandem reaction between allene esters 1, Selectfluor,
and water is proposed (Scheme 3). Firstly, the activation of the allene moiety of 1 by gold(I) species
was followed by the nucleophilic addition of H2O to 1 to form an organogold(I) intermediate
B.23,29−35,39−43 The withdrawing ester group was helpful for the regioselective addition of water to the
4-position of 1 rather than the 2-position. Then B was oxidized into an organogold(III) species C in the
presence of Selectfluor (Path I).29−35 Alternatively, C could also be generated by a hydroxyauration
reaction of allene 1 with H2O and a cationic gold(III) species arising from the oxidation of Au(I) with
Selectfluor (Path II).29−34 Cycloauration of C followed by reductive elimination of the resulting
organogold(III) cycle D gave an intermediate E.32−35 A consecutive process of 1,3-H shift of the indene
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ring48 and oxidation of hydroxy into carbonyl group49 of E followed by
ketone finally formed fluoroindene 2.
α
-fluorination50 of the resulting
In summary, a simultaneous formation of C−C, C=O, and C−F bonds has been achieved in the
gold-catalyzed three-component tandem reaction between allene esters, Selectfluor, and water. The
10
ACS Paragon Plus Environment

Page 11 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
present reaction allows for the synthesis of a variety of fluoroindenes in moderate to good yields from
simple and readily available starting materials.
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
EXPERIMENTAL SECTION
General: Unless otherwise stated, all reagents were purchased from commercial suppliers and used
without purifications. All solvents for the reactions were dried and distilled prior to use according to
standard methods. Melting points are uncorrected. The 1H NMR and 13C NMR spectra were recorded at
19
25 °C in CDCl3 at 500 MHz and 125 MHz, respectively, with TMS as the internal standard. F NMR
spectra were recorded at 25 °C in CDCl3 at 376 MHz, with CF3COOH as external standard. Chemical
shifts (δ) are expressed in ppm and coupling constants J are given in Hz. The IR spectra were recorded
on an FT-IR spectrometer. GC-MS experiments were performed with EI source, LC-MS experiments
were performed with ESI source, and high resolution mass spectra (HRMS) were obtained on a TOF
MS instrument with ESI or EI source.
General Procedure for the Gold-Catalyzed Three-Component Tandem Reaction between
Allene Esters (1), Selectfluor, and Water. In a 10-mL flask, Ph3PAuNTf2 (7.4 mg, 0.01 mmol),
Selectfluor (141 mg, 0.4 mmol), NaHCO3 (34 mg, 0.4 mmol), H2O (72 mg, 4 mmol), and CH3CN (1
mL) were added. The mixture was stirred at rt for 5 min before a CH3CN solution (1 mL) of 1 (0.2
mmol) was added. Then the mixture was stirred at 60 °C for 4 h. Upon completion, the resulting
mixture was diluted with CH2Cl2 (10 mL) and filtered through Celite. After evaporation of the solvent
11
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 12 of 25
1
2
3
4
5
6
under vacuum, the residue was purified by column chromatography on silica gel (100-200 mesh) using
petroleum ether-EtOAc (6:1, v/v) as the eluent to give pure 2.
7
8
9
Ethyl 1ꢀacetylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2a). Purification by column chromatography
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(petroleum ether/EtOAc, 6/1) as a pale white solid (36.2 mg, 73%); Rf = 0.68; IR (KBr):
ν = 1715
(C=O) cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.78 (s, 1H), 7.45−7.38 (m, 4H), 4.34−4.26 (m, 2H), 2.30
13
(d, J = 4.0 Hz, 3H), 1.35 (t, J = 7.0 Hz, 3H); C NMR (CDCl3, 125 MHz): δ 201.8 (d, J = 28.8 Hz),
162.2, 146.5 (d, J = 3.8 Hz), 141.8 (d, J = 18.8 Hz), 140.3, 137.4 (d, J = 17.5 Hz), 131.0, 130.0, 124.8,
123.4, 103.0 (d, J = 198.8 Hz), 61.2, 25.4, 14.1; 19F NMR (CDCl3, 376 MHz): δ –177.0 (s); LC-MS
(ESI): m/z 271.10 [M+Na]+; HRMS (ESI) for C14H14FO3 [M+H]+: calcd. 249.0927, found 249.0919;
mp 63−65 ºC.
Ethyl 1ꢀfluoroꢀ1ꢀpropionylꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2b). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow solid (35.7 mg, 68%); Rf = 0.60; IR (KBr):
ν = 1714 (C=O)
1
cm-1; H NMR (CDCl3, 500 MHz): δ 7.77 (s, 1H), 7.44−7.33 (m, 4H), 4.34−4.21 (m, 2H), 2.77−2.60
(m, 2H), 1.32 (t, J = 7.3 Hz, 3H), 1.08 (t, J = 7.0 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ 204.7 (d, J =
27.5 Hz), 162.3, 146.5 (d, J = 3.8 Hz), 142.1 (d, J = 18.8 Hz), 140.3, 137.5 (d, J = 17.5 Hz), 130.9,
129.9, 124.8, 123.4, 103.1 (d, J = 197.5 Hz), 61.2, 31.1, 14.1, 7.4; 19F NMR (CDCl3, 376 MHz): δ
–178.4 (s); LC-MS (ESI): m/z 285.07 [M+Na]+; HRMS (ESI) for C15H16FO3 [M+H]+: calcd. 263.1083,
found 263.1075; mp 52−54 ºC.
Ethyl 1ꢀbutyrylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2c). Purification by column chromatography
12
ACS Paragon Plus Environment

Page 13 of 25
The Journal of Organic Chemistry
1
2
3
4
(petroleum ether/EtOAc, 6/1) as a yellow liquid (46.4 mg, 84%); Rf = 0.68; IR (neat):
ν = 1713 (C=O)
5
6
7
1
cm-1; H NMR (CDCl3, 500 MHz): δ 7.77 (s, 1H), 7.43−7.28 (m, 4H), 4.34−4.23 (m, 2H), 2.65−2.59
8
9
13
(m, 2H), 1.63−1.61 (m, 2H), 1.32 (t, J = 7.3 Hz, 3H), 0.88 (t, J = 7.0 Hz, 3H); C NMR (CDCl3, 125
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
MHz): δ 203.7 (d, J = 27.5 Hz), 162.3, 146.4 (d, J = 3.8 Hz), 142.0 (d, J = 18.8 Hz), 140.3, 137.6 (d, J
= 17.5 Hz), 130.9, 129.9, 124.8, 123.4, 103.1 (d, J = 198.8 Hz), 61.1, 39.4, 30.9, 16.6, 14.1, 13.5; 19F
NMR (CDCl3, 376 MHz): δ –178.4 (s); LC-MS (ESI): m/z 277.05 [M+H]+; HRMS (ESI) for
C16H18FO3 [M+H]+: calcd. 277.1240, found 277.1237.
Ethyl 1ꢀfluoroꢀ1ꢀpentanoylꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2d). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow liquid (36.6 mg, 63%); Rf = 0.60; IR (neat):
ν = 1715 (C=O)
1
cm-1; H NMR (CDCl3, 500 MHz): δ 7.77 (s, 1H), 7.44−7.33 (m, 4H), 4.34−4.23 (m, 2H), 2.67−2.58
(m, 2H), 1.60−1.54 (m, 2H), 1.34−1.23 (m, 5H), 0.86 (t, J = 7.3 Hz, 3H); 13C NMR (CDCl3, 125 MHz):
δ 203.8 (d, J = 28.8 Hz), 162.3, 146.5 (d, J = 5.0 Hz), 142.1 (d, J = 18.8 Hz), 140.3, 137.6 (d, J = 17.5
Hz), 130.9, 129.9, 124.8, 123.4, 103.1 (d, J = 198.75 Hz), 61.1, 37.2, 25.2, 22.1, 14.1, 13.7; 19F NMR
(CDCl3, 376 MHz): δ –178.3 (s); LC-MS (ESI): m/z 313.04 [M+Na]+; HRMS (ESI) for C17H20FO3
[M+H]+: calcd. 291.1396, found 291.1411.
Ethyl 1ꢀfluoroꢀ1ꢀhexanoylꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2e). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow liquid (26.8 mg, 44%); Rf = 0.50; IR (neat):
ν = 1717 (C=O)
1
cm-1; H NMR (CDCl3, 500 MHz): δ 7.78 (s, 1H), 7.44−7.33 (m, 4H), 4.32−4.24 (m, 2H), 2.63−2.59
(m, 2H), 1.59−1.56 (m, 2H), 1.34−1.23 (m, 7H), 0.86 (t, J = 7.3 Hz, 3H); 13C NMR (CDCl3, 125 MHz):
13
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 14 of 25
1
2
3
4
5
6
7
8
9
δ 203.9 (d, J = 27.5 Hz), 162.3, 146.6 (d, J = 5.0 Hz), 142.0 (d, J = 18.8 Hz), 140.3, 137.5 (d, J = 17.5
Hz), 130.9, 129.9, 124.8, 123.4, 103.1 (d, J = 198.8 Hz), 61.2, 37.4, 31.1, 22.8, 22.4, 14.2, 13.9; 19F
NMR (CDCl3, 376 MHz): δ –178.3 (s); LC-MS (ESI): m/z 327.09 [M+Na]+; HRMS (ESI) for
C18H22FO3 [M+H]+: calcd. 305.1553, found 305.1560.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Ethyl 1ꢀfluoroꢀ1ꢀheptanoylꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2f). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow liquid (38.8 mg, 61%); Rf = 0.60; IR (neat):
ν = 1716 (C=O)
1
cm-1; H NMR (CDCl3, 500 MHz): δ 7.77 (s, 1H), 7.43−7.35 (m, 4H), 4.31−4.26 (m, 2H), 2.65−2.59
(m, 2H), 1.60−1.55 (m, 2H), 1.34−1.22 (m, 9H), 0.85 (t, J = 7.0 Hz, 3H); 13C NMR (CDCl3, 125 MHz):
δ 203.8 (d, J = 27.5 Hz), 162.3, 146.5 (d, J = 5.0 Hz), 142.0 (d, J = 18.8 Hz), 140.3, 137.5 (d, J = 17.5
Hz), 130.9, 129.9, 124.8, 123.4, 103.1 (d, J = 197.5 Hz), 61.1, 37.5, 31.5, 28.6, 23.1, 22.4, 14.2, 14.0;
19F NMR (CDCl3, 376 MHz): δ –178.4 (s); LC-MS (ESI): m/z 341.09 [M+Na]+; HRMS (ESI) for
C19H24FO3 [M+H]+: calcd. 319.1709, found 319.1700.
Ethyl 1ꢀfluoroꢀ1ꢀ(2ꢀphenylacetyl)ꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2g). Purification by column
chromatography (petroleum ether/EtOAc, 6/1) as a yellow liquid (29.9 mg, 45%); Rf = 0.60; IR (neat):
ν
= 1714 (C=O) cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.79 (s, 1H), 7.43−7.26 (m, 6H), 7.19 (d, J = 6.5
Hz, 2H), 6.96 (d, J = 7.5 Hz, 1H), 4.25 (q, J = 7.0 Hz, 2H), 4.06 (dd, J1 = 2.5 Hz, J2 = 15.5 Hz, 1H),
3.90 (dd, J1 = 3.0 Hz, J2 = 15.5 Hz, 1H), 1.32 (t, J = 7.0 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ 201.5
(d, J = 28.8 Hz), 162.3, 146.6 (d, J = 3.8 Hz), 142.0 (d, J = 18.8 Hz), 140.4, 137.5 (d, J = 17.5 Hz),
132.7, 130.9, 129.9, 128.5, 127.2, 124.8, 123.8, 103.4 (d, J = 200 Hz), 61.2, 44.8, 14.1; 19F NMR
14
ACS Paragon Plus Environment

Page 15 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
(CDCl3, 376 MHz): δ –176.8 (s); LC-MS (ESI): m/z 346.94 [M+Na]+; HRMS (ESI) for C20H18FO3
[M+H]+: calcd. 325.1240, found 325.1231.
7
8
9
Ethyl 1ꢀbenzoylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2h). Purification by column chromatography
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(petroleum ether/EtOAc, 6/1) as a yellow solid (41.0 mg, 66%); Rf = 0.60; IR (KBr):
ν = 1710 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.85−7.81 (m, 3H), 7.56−7.34 (m, 7H), 4.27−4.17 (m, 2H), 1.22 (t,
13
J = 7.0 Hz, 3H); C NMR (CDCl3, 125 MHz): δ 194.3 (d, J = 27.5 Hz), 162.1, 146.5 (d, J = 5.0 Hz),
142.7 (d, J = 17.5 Hz), 140.5, 138.9 (d, J = 16.3 Hz), 135.1, 133.1, 131.1, 130.1, 129.0 (d, J = 5.0 Hz),
128.4, 125.1, 124.4, 103.2 (d, J = 196.3 Hz), 61.1, 14.0; 19F NMR (CDCl3, 376 MHz): δ –168.4 (s);
LC-MS (ESI): m/z 333.05 [M+Na]+; HRMS (ESI) for C19H16FO3 [M+H]+: calcd. 311.1083, found
311.1069; mp 92−95 ºC.
Methyl 1ꢀacetylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2i). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a brown solid (30.0 mg, 64%); Rf = 0.60; IR (KBr):
ν = 1720 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.78 (s, 1H), 7.45−7.38 (m, 4H), 3.84 (s, 3H), 2.29 (d, J = 4.0 Hz,
3H); 13C NMR (CDCl3, 125 MHz): δ 201.7 (d, J = 28.8 Hz), 162.7, 146.8 (d, J = 5.0 Hz), 141.8 (d, J =
17.5 Hz), 140.2, 137.0 (d, J = 17.5 Hz), 131.0, 130.1, 124.9, 123.5, 103.0 (d, J = 198.8 Hz), 52.1, 25.3;
19F NMR (CDCl3, 376 MHz): δ –177.1 (s); LC-MS (ESI): m/z 257.03 [M+Na]+; HRMS (ESI) for
C13H12FO3 [M+H]+: calcd. 235.0770, found 235.0764; mp 67−69 ºC.
Propyl 1ꢀacetylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2j). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a white liquid (45.1 mg, 86%); Rf = 0.50; IR (neat):
ν = 1717 (C=O)
15
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 16 of 25
1
2
3
4
5
6
7
8
9
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.77 (s, 1H), 7.43−7.35 (m, 4H), 4.22−4.14 (m, 2H), 2.26 (d, J =
3.5 Hz, 3H), 1.75−1.69 (m, 2H), 0.97 (t, J = 7.5 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ 201.5 (d, J =
28.8 Hz), 162.2, 146.5 (d, J = 3.75 Hz), 141.7 (d, J = 18.8 Hz), 140.2, 137.4 (d, J = 17.5 Hz), 130.9,
129.9, 124.8, 123.3, 102.9 (d, J = 198.8 Hz), 66.7, 25.2, 21.9, 10.3; 19F NMR (CDCl3, 376 MHz): δ
–177.1 (s); LC-MS (ESI): m/z 285.20 [M+Na]+; HRMS (ESI) for C15H16FO3 [M+H]+: calcd. 263.1083,
found 263.1075.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Isopropyl 1ꢀacetylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2k). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow solid (44.0 mg, 84%); Rf = 0.50; IR (KBr):
ν = 1710 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.73 (s, 1H), 7.40−7.33 (m, 4H), 5.15−5.10 (m, 1H), 2.26 (d, J =
4.0 Hz, 3H), 1.29 (dd, J1 = 6.0 Hz, J2 = 11.5 Hz, 6H); 13C NMR (CDCl3, 125 MHz): δ 201.6 (d, J =
30.0 Hz), 161.7, 146.2 (d, J = 5.0 Hz), 141.7 (d, J = 20.0 Hz), 140.3 (d, J = 2.5 Hz), 137.8 (d, J = 17.5
Hz), 130.9, 129.8, 124.7, 123.3, 102.9 (d, J = 197.5 Hz), 68.8, 25.2, 21.69, 21.65; 19F NMR (CDCl3,
376 MHz): δ –177.0 (s); LC-MS (ESI): m/z 285.05 [M+Na]+; HRMS (ESI) for C15H16FO3 [M+H]+:
calcd. 263.1083, found 263.1077; mp 52−54 ºC.
Butyl 1ꢀacetylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2l). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow liquid (44.7 mg, 81%); Rf = 0.60; IR (neat):
ν = 1715 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.76 (s, 1H), 7.43−7.35 (m, 4H), 4.27−4.19 (m, 2H), 2.26 (d, J =
3.5 Hz, 3H), 1.69−1.65 (m, 2H), 1.42−1.40 (m, 2H), 0.95 (t, J = 7.5 Hz, 3H); 13C NMR (CDCl3, 125
MHz): δ 201.5 (d, J = 28.75 Hz), 162.2, 146.5 (d, J = 5.0 Hz), 141.7 (d, J = 18.8 Hz), 140.3 (d, J = 1.3
16
ACS Paragon Plus Environment

Page 17 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
Hz), 137.4 (d, J = 17.5 Hz), 130.9, 129.9, 124.8, 123.4, 102.9 (d, J = 197.5 Hz), 65.0, 30.5, 25.2, 19.0,
13.6; 19F NMR (CDCl3, 376 MHz): δ –177.1 (s); LC-MS (ESI): m/z 299.17 [M+Na]+; HRMS (ESI) for
C16H18FO3 [M+H]+: calcd. 277.1240, found 277.1230.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Allyl 1ꢀacetylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2m). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow liquid (36.9 mg, 71%); Rf = 0.60; IR (neat):
ν = 1720 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.81 (s, 1H), 7.45−7.39 (m, 4H), 6.00−5.94 (m, 1H), 5.39 (dd, J1
= 1.5 Hz, J2 = 17.0 Hz, 1H), 5.29 (dd, J1 = 1.0 Hz, J2 = 17.0 Hz, 1H), 4.76−4.74 (m, 2H), 2.31 (d, J =
3.5 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ 201.8 (d, J = 28.8 Hz), 161.9, 146.9 (d, J = 5.0 Hz), 141.9
(d, J = 18.5 Hz), 140.3, 137.1 (d, J = 17.5 Hz), 131.6, 131.0, 130.1, 124.9, 123.5, 118.8, 103.0 (d, J =
198.8 Hz), 65.7, 25.5; 19F NMR (CDCl3, 376 MHz): δ –176.9 (s); LC-MS (ESI): m/z 283.09 [M+Na]+;
HRMS (ESI) for C15H14FO3 [M+H]+: calcd. 261.0927, found 261.0934.
Methyl 1ꢀfluoroꢀ1ꢀpentanoylꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2n). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow liquid (22.6 mg, 41%); Rf = 0.60; IR (neat):
ν = 1720 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.78 (s, 1H), 7.45−7.34 (m, 4H), 3.83 (s, 3H), 2.67−2.60 (m, 2H),
1.59−1.56 (m, 2H), 1.28−1.25 (m, 2H), 0.86 (t, J = 7.3 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ 203.7
(d, J = 27.5 Hz), 162.7, 146.7 (d, J = 3.8 Hz), 142.0 (d, J = 18.8 Hz), 140.3 (d, J = 1.3 Hz), 137.2 (d, J
= 17.5 Hz), 130.9, 129.9, 124.8, 123.4, 103.1 (d, J = 198.8 Hz), 52.0, 37.1, 25.2, 22.1, 13.7; 19F NMR
(CDCl3, 376 MHz): δ –178.3 (s); LC-MS (ESI): m/z 299.06 [M+Na]+; HRMS (ESI) for C16H18FO3
[M+H]+: calcd. 277.1240, found 277.1232.
17
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 18 of 25
1
2
3
4
Methyl 1ꢀbenzoylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2o). Purification by column chromatography
5
6
7
(petroleum ether/EtOAc, 6/1) as a yellow solid (44.4 mg, 75%); Rf = 0.60; IR (KBr):
ν = 1713 (C=O)
8
9
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.85 (d, J = 7.5 Hz, 2H), 7.81 (s, 1H), 7.57−7.34 (m, 7H), 3.77 (s,
3H); 13C NMR (CDCl3, 125 MHz): δ 194.3 (d, J = 27.5 Hz), 162.6, 146.3 (d, J = 5.0 Hz), 142.7 (d, J =
17.5 Hz), 140.5, 138.6 (d, J = 17.5 Hz), 135.2, 133.2, 131.1, 130.2, 129.0 (d, J = 5.0 Hz), 128.5, 125.2,
124.4, 103.3 (d, J = 197.5 Hz), 52.0; 19F NMR (CDCl3, 376 MHz): δ –169.7 (s); LC-MS (ESI): m/z
319.10 [M+Na]+; HRMS (ESI) for C18H14FO3 [M+H]+: calcd. 297.0927, found 297.0917; mp 115−117
ºC.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Ethyl 1ꢀacetylꢀ1ꢀfluoroꢀ6ꢀmethylꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2p). Purification by column
chromatography (petroleum ether/EtOAc, 6/1) as a yellow solid (39.8 mg, 76%); Rf = 0.60; IR (KBr):
ν
1
= 1714 (C=O) cm-1; H NMR (CDCl3, 500 MHz): δ 7.71 (s, 1H), 7.23−7.14 (m, 3H), 4.32−4.21 (m,
2H), 2.36 (s, 3H), 2.24 (d, J = 3.5 Hz, 3H), 1.31 (t, J = 7.3 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ
201.4 (d, J = 30.0 Hz), 161.8, 144.9 (d, J = 5.0 Hz), 142.1 (d, J = 1.3 Hz), 140.0 (d, J = 18.8 Hz), 139.1
(d, J = 17.5 Hz), 137.2, 129.7, 125.1, 124.4, 102.3 (d, J = 200.0 Hz), 61.4, 25.5, 14.1; 19F NMR (CDCl3,
376 MHz): δ –176.3 (s); LC-MS (ESI): m/z 284.99 [M+Na]+; HRMS (ESI) for C15H16FO3 [M+H]+:
calcd. 263.1083, found 263.1075; mp 76−78 ºC.
Ethyl 1ꢀacetylꢀ6ꢀchloroꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2q). Purification by column
chromatography (petroleum ether/EtOAc, 6/1) as a white solid (38.9 mg, 69%); Rf = 0.60; IR (KBr):
ν
1
= 1717 (C=O) cm-1; H NMR (CDCl3, 500 MHz): δ 7.69 (s, 1H), 7.42 (d, J = 1.5 Hz, 1H), 7.36−7.29
18
ACS Paragon Plus Environment

Page 19 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
(m, 2H), 4.36−4.25 (m, 2H), 2.33 (d, J = 4.0 Hz, 3H), 1.34 (t, J = 7.5 Hz, 3H); 13C NMR (CDCl3, 125
MHz): δ 201.4 (d, J = 30 Hz), 161.8, 144.9 (d, J = 3.8 Hz), 142.1 (d, J = 1.3 Hz), 140.0 (d, J = 20.0 Hz),
139.1 (d, J = 17.5 Hz), 137.2, 129.7, 125.1, 124.4, 102.3 (d, J = 200 Hz), 61.4, 25.5, 14.1; 19F NMR
(CDCl3, 376 MHz): δ –176.5 (s); LC-MS (ESI): m/z 305.02 [M+Na]+; HRMS (ESI) for C14H13ClFO3
[M+H]+: calcd. 283.0537, found 283.0525; mp 135−137 ºC.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Ethyl 1ꢀacetylꢀ6ꢀbromoꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2r). Purification by column
chromatography (petroleum ether/EtOAc, 6/1) as a yellow solid (39.8 mg, 69%); Rf = 0.60; IR (KBr):
ν
= 1717 (C=O) cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.67 (s, 1H), 7.56 (d, J = 1.5 Hz, 1H), 7.50 (dd, J1
= 1.5 Hz, J2 = 7.5 Hz, 1H), 7.22 (dd, J1 = 1.0 Hz, J2 = 8.0 Hz, 1H), 4.32−4.27 (m, 2H), 2.31 (d, J = 4.0
Hz, 3H), 1.33 (t, J = 7.0 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ 201.3 (d, J = 28.8 Hz), 161.8, 144.9
(d, J = 5.0 Hz), 142.3, 140.5 (d, J = 18.8 Hz), 138.9 (d, J = 17.5 Hz), 132.6, 127.9, 125.1, 124.7, 102.4
(d, J = 198.8 Hz), 61.4, 25.5, 14.1; 19F NMR (CDCl3, 376 MHz): δ –176.7 (s); LC-MS (ESI): m/z
348.92 [M+Na]+; HRMS (ESI) for C14H12BrFNaO3 [M+H]+: calcd. 348.9852, found 348.9846; mp
114−116 ºC.
3ꢀMethylꢀ3Hꢀindeno[1,2ꢀc]furanꢀ1(8H)ꢀone (3v).32 Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a white solid (21.9 mg, 59%); Rf = 0.60; IR (KBr):
ν = 1739 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.61 (d, J = 6.5 Hz, 1H), 7.50−7.41 (m, 3H), 5.56−5.50 (m, 1H),
3.61 (d, J = 3.0 Hz, 2H), 1.70 (d, J = 2.0 Hz, 3H); 13C NMR (CDCl3, 125 MHz): δ 174.2, 168.6, 149.8,
135.8, 135.3, 128.9, 127.4, 125.9, 121.6, 75.6, 32.2, 19.2; GC-MS (EI, 70eV): m/z 186 (M+); mp
19
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 20 of 25
1
2
3
4
5
6
156−158 ºC.
3ꢀBenzylꢀ4ꢀfluoroꢀ5,5ꢀdimethylfuranꢀ2(5H)ꢀone (4w). Purification by column chromatography
7
8
9
(petroleum ether/EtOAc, 6/1) as a yellow liquid (18.0 mg, 41%); Rf = 0.60; IR (neat):
ν = 1768 (C=O),
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
1
1720 (C=O) cm-1; H NMR (CDCl3, 500 MHz): δ 7.33−7.23 (m, 5H), 3.57 (s, 2H), 1.55 (s, 6H); 13C
NMR (CDCl3, 125 MHz): δ 180.5, 178.1, 169.9 (d, J = 22.5 Hz), 136.8 (d, J =2.5 Hz), 128.6 (d, J =
27.5 Hz), 126.8, 106.6 (d, J = 5.0 Hz), 79.8 (d, J = 22.5 Hz), 29.7, 27.3 (d, J = 2.5 Hz), 23.7 (d, J = 2.5
Hz); 19F NMR (CDCl3, 376 MHz): δ –113.1 (s); GC-MS (EI, 70eV): m/z 220 (M+); HRMS (EI) for
C13H13FO2 [M+H]+: calcd. 220.0900, found 220.0907.
Ethyl 1ꢀacetylꢀ3,4ꢀdihydronaphthaleneꢀ2ꢀcarboxylate (2x). Purification by column chromatography
(petroleum ether/EtOAc, 6/1) as a yellow liquid (21.0 mg, 43%); Rf = 0.61; IR (neat):
ν = 1703 (C=O)
cm-1; 1H NMR (CDCl3, 500 MHz): δ 7.32−7.21 (m, 3H), 7.10 (d, J = 8.0 Hz, 1H), 4.27 (q, J = 7.1 Hz,
2H), 2.88 (t, J = 8.0 Hz, 2H), 2.64 (t, J = 8.1 Hz, 2H), 2.49 (s, 3H), 1.34 (t, J = 7.0 Hz, 3H); 13C NMR
(CDCl3, 125 MHz): δ 205.3, 166.5, 149.4, 137.3, 130.0, 129.7, 128.2, 127.0, 125.8, 124.3, 61.3, 31.2,
27.6, 22.5, 14.0; GC-MS (EI, 70eV): m/z 244 (M+); HRMS (EI) for C15H17O3 [M+H]+: calcd. 245.1178,
found 245.1174.
4ꢀDeuterated ethyl 1ꢀacetylꢀ1ꢀfluoroꢀ1Hꢀindeneꢀ2ꢀcarboxylate (2a-D). Purification by column
chromatography (petroleum ether/EtOAc, 6/1) as a pale white solid (35.4 mg, 71%, 70%-Deuterium
enrichment at the 4-position); Rf = 0.68; IR (KBr):
ν
= 1715 (C=O) cm-1; 1H NMR (CDCl3, 500 MHz):
δ 7.78 (s, 1H), 7.44−7.38 (m, 3.30H), 4.34−4.26 (m, 2H), 2.30 (d, J = 4.0 Hz, 3H), 1.34 (t, J = 7.0 Hz,
20
ACS Paragon Plus Environment

Page 21 of 25
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
3H); 13C NMR (CDCl3, 125 MHz): δ 201.8 (d, J = 30.0 Hz), 162.2, 146.4 (d, J = 3.8 Hz), 141.8 (d, J =
18.8 Hz), 140.3 (d, J = 13.8 Hz), 137.5 (d, J = 16.3 Hz), 130.9 (d, J = 13.8 Hz), 130.0, {124.8, 124.7,
124.5, 124.3}(1C, 2a-D plus 2a), 123.4, 103.0 (d, J = 197.5 Hz), 61.2, 25.4, 14.1; LC-MS (ESI): m/z
272.19 [M+Na]+; HRMS (ESI) for C14H13DFO3 [M+H]+: calcd. 250.0990, found 250.0983; mp 63−65
ºC.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ACKNOWLEDGMENT
Financial support from the Natural Science Foundation of China (No. 21172197) and Zhejiang
Province (No. Y4100201), the Foundation of Science and Technology Department of Zhejiang
Province (2011R09002-09), and the Opening Foundation of Zhejiang Provincial Top Key Discipline is
gratefully acknowledged.
SUPPORTING INFORMATION
The experimental procedures for the synthesis of starting materials and their characterization, copies
1
19
of H NMR, 13C NMR, and F NMR spectra of the products as well as X-ray structural data (CIF) of
compound 2q. This material is available free of charge via the Internet at http://pubs.acs.org.
REFERENCES
(1) Korte, A.; Legros, J.; Bolm, C. Synlett 2004, 2397-2399, and references therein.
21
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 22 of 25
1
2
3
4
5
6
7
8
9
(2) He, Y.; Chen, H.-Y.; Hou, J.; Li, Y. J. Am. Chem. Soc. 2010, 132, 1377-1382.
(3) Uneyama, K. Organofluorine Chemistry; Blackwell: Oxford, UK, 2006.
(4) Gerhard, J.; Volker, K.; Martin, B.; Matthias, G. C2ꢀDisubstituted Indaneꢀ1ꢀol Systems and Their
Use as Medicaments. Eur. Pat. Appl. 1425264, 2004.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(5) Melanie, K.-M.; Lars, L.; Matthias, B. Liquid Medium Containing Fluorinated Indane
Compounds. U.S. Patent 2007080324, April 12, 2007, and references therein.
(6) Liu, C.-R.; Yang, F.-L.; Jiu, Y.-Z.; Ma, X.-T.; Cheng, D.-J.; Li, N.; Tian, S.-K. Org. Lett. 2010,
12, 3832-3835, and references therein.
(7) Marion, N.; Díez-González, S.; de Frémont, P.; Noble, A. R.; Nolan, S. P. Angew. Chem., Int. Ed.
2006, 45, 3647-3650.
(8) Pan, X.; Luo, Y.; Liu, G.; Pu, S.; Wu, J. Adv. Synth. Catal. 2012, 354, 171-178.
(9) Nie, J.; Zhu, H.-W.; Cui, H.-F.; Hua, M.-Q.; Ma, J.-A. Org. Lett. 2007, 9, 3053-3056.
(10) Cui, H.-F.; Dong, K.-Y.; Zhang, G.-W.; Wang, L.; Ma, J.-A. Chem. Commun. 2007, 1184-2286.
(11) Haas, A.; Hoppmann, E.; Karpov, V. M.; Platonov, V. E.; Shakirov, M. M. J. Fluorine Chem.
2000, 102, 313-316.
(12) Moss, R. A.; Xue, S.; Sauers, R. R. J. Am. Chem. Soc. 1996, 118, 10307-10308.
(13) Fuchibe, K.; Mitomi, K.; Suzuki, R.; Akiyama, T. Chem.
 Asian J. 2008, 3, 261-271.
22
ACS Paragon Plus Environment

Page 23 of 25
The Journal of Organic Chemistry
1
2
3
4
(14) Dolbier, Jr., W. R.; Palmer, K.; Koroniak, H.; Zhang, H.-Q. J. Am. Chem. Soc. 1991, 113,
5
6
7
1059-1061.
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(15) Lee, C.-C.; Lin, S.-T.; Ke, S.-Y. Tetrahedron 2007, 63, 120-125.
(16) Mezhenkova, T. V.; Karpov, V. M.; Platonov, V. E.; Gatilov, Y. J. Fluorine Chem. 2009, 130,
951-958.
(17) Mezhenkova, T. V.; Karpov, V. M.; Platonov, V. E. Russ. J. Org. Chem. 2010, 46, 1418-1420.
(18) Ichikawa, J.; Sakoda, K.; Mihara, J.; Ito, N. J. Fluorine Chem. 2006, 127, 489-504.
(19) Dolvbier, Jr., W. R.; Palmer, K. W. J. Org. Chem. 1993, 58, 7064-7069.
(20) Hashmi, A. S. K.; Grundl, L. Tetrahedron 2005, 61, 6231-6236.
(21) Hashmi, A. S. K.; Bührle, M.; Wölfle, M.; Rudolph, M.; Wieteck, M.; Rominger, F.; Frey, W.
Chem.
Eur. J. 2010, 16, 9846-9854.
(22) Hashmi, A. S. K.; Häffner, T.; Rudolph, M.; Rominger, F. Chem.
Eur. J. 2011, 17,
8195-8201.
(23) Krause, N.; Winter, C. Chem. Rev. 2011, 111, 1994-2009.
(24) Corma, A.; Leyva-Pérez, A.; Sabater, M. J. Chem. Rev. 2011, 111, 1657-1712.
(25) Boorman, T. C.; Larrosa, I. Chem. Soc. Rev. 2011, 40, 1910-1925.
(26) Bandini, M. Chem. Soc. Rev. 2011, 40, 1358-1367, and references therein.
23
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 24 of 25
1
2
3
4
5
6
(27) Hashmi, A. S. K.; Rudolph, M. Chem. Soc. Rev. 2008, 37, 1766-1775.
(28) Rudolph, M.; Hashmi, A. S. K. Chem. Soc. Rev. 2012, 41, 2448-2462.
7
8
9
(29) Hopkinson, M. N.; Gee, A. D.; Gouverneur, V. Chem.
Eur. J. 2011, 17, 8248-8262.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(30) Wegner, H. A.; Auzias, M. Angew. Chem., Int. Ed. 2011, 50, 8236-8247.
(31) Garcia, P.; Malacria, M.; Aubert, C.; Gandon, V.; Fensterbank, L. ChemCatChem 2010, 2,
493-497.
(32) Hopkinson, M. N.; Tessier, A.; Salisbury, A.; Giuffredi, G. T.; Combettes, L. E.; Gee, A. D.;
Gouverneur, V. Chem. Eur. J. 2010, 16, 4739-4743.
(33) Qian, J.; Liu, Y.; Zhu, J.; Jiang, B.; Xu, Z. Org. Lett. 2011, 13, 4220-4223.
(34) Wang, W.; Jasinski, J.; Hammond, G. B.; Xu, B. Angew. Chem., Int. Ed. 2010, 49, 7247-7252.
(35) Zhang, G.; Luo, Y.; Wang, Y.; Zhang, L. Angew. Chem., Int. Ed. 2011, 50, 4450-4454.
(36) For the first description of an F+-induced C−C bond formation, see: Hashmi, A. S. K.;
Ramamurthi, T. D.; Rominger, F. J. Organomet. Chem. 2009, 694, 592-597.
(37) Hashmi, A. S. K.; Ramamurthi, T. D.; Todd, M. H.; Tsang, A. S.-K.; Graf, K. Aust. J. Chem.
2010, 63, 1619-1626.
(38) For the first paper on gold-catalyzed reactions of allenes, see: Hashmi, A. S. K.; Schwarz, L.;
Choi, J.-H.; Frost, T. M. Angew. Chem., Int. Ed. 2000, 39, 2285-2288.
(39) For selected examples on gold(I)-catalyzed cyclization of allenes, see: Tarselli, M. A.; Gagné, M.
R. J. Org. Chem. 2008, 73, 2439-2441. Also see ref 40−42.
24
ACS Paragon Plus Environment

Page 25 of 25
The Journal of Organic Chemistry
1
2
3
4
(40) Weber, D.; Gagné, M. R. Org. Lett. 2009, 11, 4962-4965.
5
6
7
(41) Liu, C.; Widenhoefer, R. A. Org. Lett. 2007, 9, 1935-1938.
8
9
(42) Weber, D.; Tarselli, M. A.; Gagné, M. R. Angew. Chem., Int. Ed. 2009, 48, 5733-5736.
(43) For Pt-catalyzed hydroarylation of allene esters, see: Mo, J.; Lee, P. H. Org. Lett. 2010, 12,
2570-2573.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(44) For gold(I)-catalyzed cyclization of allene esters leading to stable vinylgold compounds, see:
Liu, L.-P.; Xu, B.; Mashuta, M.; Hammond, G. B. J. Am. Chem. Soc. 2008, 130, 17642-17643. Also see
ref 45.
(45) Döpp, R.; Lothschütz, C. Wurm, T.; Pernpointner, M.; Keller, S.; Rominger, F.; Hashmi, A. S. K.
Organometallics 2011, 30, 5894-5903.
(46) For a fluorinative silver-catalyzed hydroamination of allenes, see: Xu, T.; Mu, X.; Peng, H.; Liu,
G. Angew. Chem., Int. Ed. 2011, 50, 8176-8179.
(47) Hashmi, A. S. K. Angew. Chem. Int. Ed. 2010, 49, 5232-5241.
(48) Hussenius, A.; Matsson, O. Acta Chem. Scand. 1990, 44, 845-850.
(49) Pina, C. D.; Falletta, E.; Rossi, M. Oxidation of alcohols and carbohydrates. In Modern Gold
Catalyzed Synthesis; Hashmi, A. S. K., Toste, D. F., Eds.; Wiley-VCH: Weinheim, 2012; pp 309-330.
(50) Stavber, G.; Stavber, S. Adv. Synth. Catal. 2010, 352, 2838-2846.
25
ACS Paragon Plus Environment